updated
advertisem*nt
Apartments abound in the new city area called San Myshuno. Sims are not required to inhabit them even if they take one of the new City Living Careers. Sims can freely move to or from apartments and the suburbs as long as they have the money to cover the costs.
Apartment Pros and Cons
Apartments are much cheaper than houses, and all apartments come with furniture already. The main downside of apartments is they are not expandable: if you move into a single-bedroom apartment and plan on having a family, thing will get cramped awfully quickly!
Still, there are apartments of different costs and sizes. You can preview all apartments regardless of where your current family lives by clicking into each of the apartment towers. You can then see a cutaway of each apartment (though you can't zoom the camera closer) and at least see the arrangement of furniture and walls.
advertisem*nt
San Myshuno also features a few penthouse apartments. These are incredible expensive and comprised of multiple floors, but they feature high-end furnishings for wealthy Sims!
Apartments require deposits and weekly rent, which take the place of standard bills. The weekly rent fee is a double-edged sword, as it's not affected by what you have in the apartment. This means that early on, a few of the weekly rent costs may be high; Generation 1 Sims will struggle to afford anything but the smallest, cheapest apartments. However, as they accumulate wealth and upgrade their furniture, the bills will not go up. In the long-term, this means your Sim will save more money living in apartment simply because less of their simoleons will be eaten up by bills.
All the apartment towers exist within the four districts of San Myshuno. Each district has its own unique community buildings, but districts can be visited at will no matter where you live. Everything in San Myshuno can be reached and is viewable from its neighborhood screen.
Keys to Friends
Most apartments have neighbors who may or may not make noise at night (through either loud music or Woo Hooing), which will completely shut down your Sim's ability to sleep. If this happens, you can order your Sim to pound on the door and complain, though that's no guarantee it'll work.
If you want a little revenge, or if you simply need some friends to keep you from going stir-crazy in a tiny apartment, you can give any friend a key to your apartment with a Friendly-type social interaction. When a Sim has a key, they will randomly pop over generally once a day. Note that if a Sim has a key, they are treated as a normal member of your family, so they can do actions like checking your fridge or taking showers without causing anyone an anti-social debuff.
advertisem*nt
Keys to friends has no direct benefit other than having a close relationship stop by often. Keys cannot be given to friends for houses in the suburbs in this way.
Lot Traits
The City Living Expansion Pack added Lot Traits. All apartments have multiple lot traits, but these can be changed at will in Build Mode. Lot Traits can be assigned or unassigned to other lots, including houses in the suburbs. Check out the Lot Traits page for more information on them.
advertisem*nt
Some Lot Traits may trigger randomly while others are constant. If it's a randomly triggering trait, the trait tends to trigger often (at least once every two days or even every day). Keep that in mind when you're viewing the traits when you formulate a plan on where to live.
Two apartments that are next to each other even within the same tower may have conflicting or nonsensical traits. In other words, each lot's traits are independent of every other lot.
